Homepage for USGS national surface-water data with more than 850,000 station years of time-series data for stream levels, streamflow (discharge), reservoir and lake levels, surface-water quality, and rainfall plus real-time data and tutorial.

Homepage of the Office of Water Quality programs on the quality of the Nation's surface water and ground water resources, with links to general information, quality assurance, software, data, publications, USGS facilities, techniques, and programs.

Stream discharge and nitrate concentration increased downstream of the burned area during snowmelt, but these were probably within the treatment capacity of most drinking-water plants, and limited changes were observed in downstream ecosystems.

Homepage for description of the National Stream Quality Network (NASQAN), a long-term program monitoring the concentrations and flux of sediment and chemicals in the Nation's largest rivers (Mississippi, Columbia, Colorado, Rio Grande, and Yukon).